Technical Field
The present disclosure relates to a vehicle headlamp light distribution control device, a vehicle headlamp light distribution control method, and a storage medium storing a program of controlling vehicle headlamp light distribution.
Related Art
In the technique disclosed in Japanese Patent Application Laid-Open (JP-A) No. 2013-203130, a headlamp illumination pattern that is adjusted at the time of shipping-out a vehicle is stored as a reference pattern, and, when the vehicle travels, it is judged whether or not conditions for implementing adjustment of the illumination range of the headlamp are established. In a case in which adjustment of the illumination range of the headlamp is to be implemented, the image of a camera that captures images of the region in front of the vehicle is processed, the illumination pattern of the headlamp is recognized, the stored reference pattern and the recognized illumination pattern are compared, and the illumination range of the headlamp is adjusted so that the both match.
The inclination of a vehicle changes in accordance with the number of passengers and the load capacity of the cargo. When the inclination of the vehicle changes, the angle of the imaging optical axis of the imaging section such as an on-board camera that images the region in front of the vehicle changes, and the range of imaging by the imaging section also moves. Therefore, in order to control the light distribution (the illumination range) of the headlamp on the basis of the image of the front region of the vehicle that is captured by the imaging section as in the technique of above-described JP-A No. 2013-203130, a reference position within the image must be detected, and information obtained from the image (e.g., the positions of other vehicles) must be calibrated in accordance with the detected reference position. Note that, for example, the position of the Focus of Expansion (FOE), which is the intersection point of the extensions of plural optical flows within the image, or the position of the vanishing point is used as the aforementioned reference position. Hereinafter, both are referred to as the vanishing point.
However, detection of the reference point within the image is realized by image processing such as, for example, searching for plural regions that correspond to white lines on the road, and approximating, by straight lines, the respective regions extracted by the search, and determining the intersection point of the plural, approximated straight lines, or the like. Thus, time or a traveled distance of a certain extent are needed to detect the reference position. Therefore, there is the possibility that, during the time period until the reference position within the image is detected, the accuracy of the light distribution control of the lamp will deteriorate due to a change in the imaging optical axis, and there is the concern that glare will be imparted to other vehicles or the like that exist in front of the vehicle.